Effect of intensive motor training with repetitive transcranial magnetic stimulation on upper limb motor function in chronic post-stroke patients with severe upper limb motor impairment

Background Intensive motor training with low-frequency repetitive transcranial magnetic stimulation (rTMS) has efficacy as a therapeutic method for motor dysfunction of the affected upper limb in patients with mild to moderate stroke. However, it is not clear whether this combination therapy has the same effect in chronic post-stroke patients with severe upper limb motor impairment.

Objectives The aim of this study was to test the treatment effects of intensive motor training with low-frequency rTMS in chronic post-stroke patients with severe upper limb motor impairment.

Methods A convenience sample of 26 chronic post-stroke patients with severe upper limb motor impairment participated in this study with the non-randomized, non-controlled clinical trial. All subjects were hospitalized to receive intensive motor training with low-frequency rTMS. During 2 weeks in which Sundays were excluded, a total of 24 sessions (2 sessions per day) of the intervention were conducted. The Fugl–Meyer Assessment (FMA) and Wolf Motor Function Test (WMFT) were used to assess motor impairment and function of the affected upper limb, respectively, before and after intervention. Paired t-test was used to analyze the effects of the intervention.

Results The FMA total score and WMFT log performance time significantly improved from before to after intervention (FMA: 12.6–18.0; WMFT: 3.6–3.3, p < 0.001).

Conclusions The present results suggest that intensive motor training with low-frequency rTMS could improve motor impairment in chronic post-stroke patients with severe upper limb motor impairment and contribute to the expansion of the application range of this combination therapy.     

Delay in initiation and termination of muscle contraction, motor impairment, and physical disability in upper limb hemiparesis

The purpose of this study was to describe the relationship between the delay in initiation and termination of muscle contraction and clinical measures of motor impairment and physical disability in the affected upper limb of patients with hemiparesis. Electromyographic (EMG) activity of 26 long-term survivors of stroke was recorded during isometric wrist flexion and extension. Upper limb motor impairment and disability were assessed with the Fugl-Meyer motor assessment (FMA) and arm motor ability test (AMAT), respectively. Delay in initiation and termination of muscle contraction was significantly prolonged in the paretic arm. However, the delay was not significantly affected by stroke type, stroke level, side of hemiparesis, or presence of aphasia. Delay in initiation and termination of muscle contraction correlated significantly with FMA and AMAT. Abnormally delayed initiation and termination of muscle contraction may contribute to hemiparetic upper limb motor impairment and physical disability in hemiparetic patients.     

Transient improvement induced by motor fatigue in focal occupational dystonia: the handgrip test.

Muscle fatigue induced by a previous sustained contraction temporarily decreases the motor output, transiently worsening motor performance. Whether muscle fatigue alters motor performance also in dystonia-a disorder whose main pathophysiological abnormality is motor overflow-remains unknown. To assess the effects of muscle fatigue in patients with focal occupational upper limb dystonia, we studied the effect of a previous maximum fatiguing voluntary contraction on motor performance in 10 musicians with focal occupational dystonia, in 3 musicians with hand motor impairment due to non-dystonic disorders, and in 5 normal musicians. The fatiguing task consisted of grasping a spring handgrip as long as possible until the task failed. In dystonic musicians, a fatiguing contraction significantly improved motor performance. The improvement lasted less than 5 minutes and appeared only after fatigue of the affected upper limb. In contrast, in musicians with non-dystonic motor impairment, motor performance remained unchanged or worsened, and normal musician performance consistently worsened.     

Intensive sensorimotor arm training mediated by therapist or robot improves hemiparesis in patients with chronic stroke

Investigators have demonstrated that a variety of intensive movement training protocols for persistent upper limb paralysis in patients with chronic stroke (6 months or more after stroke) improve motor outcome. This randomized controlled study determined in patients with upper limb motor impairment after chronic stroke whether movement therapy delivered by a robot or by a therapist using an intensive training protocol was superior. Robotic training (n = 11) and an intensive movement protocol (n = 10) improved the impairment measures of motor outcome significantly and comparably; there were no significant changes in disability measures. Motor gains were maintained at the 3-month evaluation after training. These data contribute to the growing awareness that persistent impairments in those with chronic stroke may not reflect exhausted capacity for improvement. These new protocols, rendered by either therapist or robot, can be standardized, tested, and replicated, and potentially will contribute to rational activity-based programs.     

Transynaptic Changes Evident in Peripheral Axonal Function After Acute Cerebellar Infarct

The cerebellum has a vital role in fine motor control of the limbs. Consequently, downstream changes in peripheral axonal function may develop following a cerebellar infarct, in part, to adapt to the resultant impairment. The present study investigated changes in excitability in ipsilateral and contralateral upper limb peripheral motor axons in patients with acute cerebellar infarct to determine whether plastic changes may have functional relevance. Peripheral nerve excitability studies and detailed clinical assessments of functional impairment were undertaken in 13 patients with acute unilateral cerebellar infarct within 1 week of ictus. Changes were followed longitudinally over 1 year at 3, 6 and 12 months with results compared to 15 age-matched control subjects. Immediately following stroke, there were significant alterations in peripheral nerve excitability parameters in the upper limbs of patients compared to controls that were most evident in the more severely impaired group. There were significant correlations between excitability indices and functional scores in the entire cohort that demonstrated greater changes in axonal function associated with more impairment. Peripheral excitability trended towards normal over the study period in the context of clinical improvement. Following an acute cerebellar infarct, changes were observed in peripheral motor axons bilaterally that were more pronounced in patients with severe functional impairment. The peripheral changes may represent a functionally relevant plastic process reflecting altered activity to adapt to the disability of the stroke.     

Fugl-Meyer Assessment Scores Are Related With Kinematic Measures in People with Chronic Hemiparesis after Stroke

Background: Stroke often results in motor impairment and limited functional capacity. This study aimed to verify the relationship between widely used clinical scales and instrumented measurements to evaluate poststroke individuals with mild, moderate, and severe motor impairment. Methods: This cross-sectional study included 34 participants with chronic hemiparesis after stroke. Fugl-Meyer Assessment and Modified Ashworth Scale were used to quantify upper and lower limb motor impairment and the resistance to passive movement (i.e., spasticity), respectively. Upper limb Motor performance (movement time and velocities) and movement quality (range of motion, smoothness and trunk displacement) were analyzed during a reaching forward task using an optoelectronic system (instrumented measurement). Lower limb motor performance (gait and functional mobility parameters) was assessed by using an inertial measurement unit system. Findings: Fugl-Meyer Assessment correlated with motor performance (upper and lower limbs) and with movement quality (upper limb). Modified Ashworth scale correlated with movement quality (upper limb). Cutoff values of 9.0 cm in trunk anterior displacement and .57 m/s in gait velocity were estimated to differentiate participants with mild/moderate and severe compromise according to the Fugl-Meyer Assessment. Conclusions: These results suggest that the Fugl-Meyer Assessment can be used to infer about motor performance and movement quality in chronic poststroke individuals with different levels of impairment.     

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Damage to the motor cortex of one hemisphere has classically been associated with contralateral upper limb paresis, but recent patient studies have identified deficits in both upper limbs. In non-human primates, we tested the hypothesis that the severity of ipsilesional upper limb motor impairment in the early post-injury phase depends on the volume of gray and white matter damage of the motor areas of the frontal lobe. We also postulated that substantial recovery would accompany minimal task practice and that ipsilesional limb recovery would be correlated with recovery of the contralesional limb. Gross (reaching) and fine hand motor functions were assessed for 3–12 months post-injury using two motor tests. Volumes of white and gray matter lesions were assessed using quantitative histology. Early changes in post-lesion motor performance were inversely correlated with white matter lesion volume indicating that larger lesions produced greater decreases in ipsilesional hand movement control. All monkeys showed improvements in ipsilesional hand motor skill during the post-lesion period, with reaching skill improvements being positively correlated with total lesion volume indicating that larger lesions were associated with greater ipsilesional motor skill recovery. We suggest that reduced trans-callosal inhibition from the lesioned hemisphere may play a role in the observed skill improvements. Our findings show that significant ipsilesional hand motor recovery is likely to accompany injury limited to frontal motor areas. In humans, more pronounced ipsilesional motor deficits that invariably develop after stroke may, in part, be a consequence of more extensive subcortical white and gray matter damage.     

Muscle weakness and cocontraction in upper limb hemiparesis: relationship to motor impairment and physical disability

The purpose of this article is to describe the relationship between poststroke upper limb muscle weakness and cocontraction, and clinical measures of upper limb motor impairment and physical disability. Electrormyographic (EMG) activity of the paretic and nonparetic wrist flexors and extensors of 26 chronic stroke survivors were recorded during isometric wrist flexion and extension. The root mean square (RMS) of the EMG signal was used as a measure of strength of contraction. A ratio of RMS of antagonist and agonist muscles was used as a measure of cocontraction. Upper limb motor impairment and physical disability were assessed with the Fugl-Meyer motor assessment (FMA) and the arm motor ability test (AMAT), respectively. The strength of muscle contraction was significantly stronger in the nonparetic limb (P < 0.001). The degree of cocontraction was significantly greater in the paretic limb (P < 0.001). The strength of muscle contraction in the paretic limb correlated significantly with FMA (r = 0.62 to 0.87, P < or = 0.001) and AMAT (r = 0.66 to 0.80, P < or = 0.001) scores. Similarly, the degree of cocontraction correlated significantly with FMA (r = -0. 70 to -0.64, P < or = 0.001) and AMAT (r = -0. 72 to -0.62, P < or = 0.001) scores. Muscle weakness and degree of cocontraction correlate significantly with motor impairment and physical disability in upper limb hemiplegia. This relationship may provide insights toward development of specific interventions. However, additional studies are needed to demonstrate a cause and effect relationship.     

When is sensorimotor stroke a lacunar syndrome?

Forty five patients with clear sensorium and no neurological deficits other than unilateral motor and sensory impairment underwent computed tomography (CT). Twenty patients had sensorimotor stroke with impairment of all sensory modalities (type 1). Eight had only impairment of nociceptive sensation (type 2) and 15 had only proprioceptive impairment (type 3). Two patients had sensory impairment in one limb only (type 4). Lacunes were found in patients in the first three groups. However, 80% of those who had hemiparesis and incomplete sensory loss were found to have a lacune or normal CT scan whilst only 33% of those with complete motor or sensory impairment had lacunes. It is proposed that sensorimotor stroke as a lacunar syndrome be best restricted to those with only mild to moderate hemiparesis and sensory impairment in both upper and lower limbs. The degree and extent of sensory and motor involvement may vary, however, possibly dependent on whether the thalamo-geniculate, anterior choroidal or lateral lenticulostriate artery is affected.     

Clinical Prediction Rule for Identifying the Stroke Patients who will Obtain Clinically Important Improvement of Upper Limb Motor Function by Robot-Assisted Upper Limb

BackgroundThe number of studies on the characteristics of patients with stroke who would benefit from robot-assisted upper limb rehabilitation is limited, and there are no clear criteria for determining which individuals should receive such treatment. The current study aimed to develop a clinical prediction rule using machine learning to identify the characteristics of patients with stroke who can the achieve minimal clinically important difference of the Fugl-Meyer Upper Extremity Evaluation (FMA-UE) after single-joint hybrid assistive limb (HAL-SJ) rehabilitation.MethodsThis study included 71 patients with subacute stroke who received HAL-SJ rehabilitation. The chi-square automatic interaction detector (CHAID) model was applied to predict improvement in upper limb motor function. Based the analysis using CHAID, age, sex, days from stroke onset to the initiation of HAL-SJ rehabilitation, and upper limb motor and cognitive functions were used as independent variables. Improvement in upper limb motor function was determined based on the minimal clinically important difference of the FMA-UE, which was used as a dependent variable.ResultsAccording to the CHAID model, the FMA-UE score during the initiation of HAL-SJ rehabilitation was the most significant predictive factor for patients who are likely to respond to the intervention. Interestingly, this therapy was more effective in patients with moderate upper limb motor dysfunction and early initiation of HAL-SJ rehabilitation. The accuracy of the CHAID model was 0.89 (95% confidence interval: 0.81–0.96).ConclusionWe developed a clinical prediction rule for identifying the characteristics of patients with stroke whose upper limb motor function can improve with HAL-SJ rehabilitation.     

Effects of temporary functional deafferentation on the brain, sensation, and behavior of stroke patients

Following stroke, many patients suffer from chronic motor impairment and reduced somatosensation in the stroke-affected body parts. Recent experimental studies suggest that temporary functional deafferentation (TFD) of parts of the stroke-affected upper limb or of the less-affected contralateral limb might improve the sensorimotor capacity of the stroke-affected hand. The present study sought evidence of cortical reorganization and related sensory and motor improvements following pharmacologically induced TFD of the stroke-affected forearm. Examination was performed during 2 d of Constraint-Induced Movement Therapy. Thirty-six human patients were deafferented on the stroke-affected forearm by an anesthetic cream (containing lidocaine and prilocaine) on one of the 2 d, and a placebo cream was applied on the other. The order of TFD and placebo treatment was counterbalanced across patients. Somatosensory and motor performance were assessed using a Grating orienting task and a Shape-sorter-drum task, and with somatosensory-evoked magnetic fields. Evoked magnetic fields showed significant pre- to postevaluation magnitude increases in response to tactile stimulation of the thumb of the stroke-affected hand during TFD but not following placebo treatment. We also observed a rapid extension of the distance between cortical representations of the stroke-affected thumb and little finger following TFD but not following placebo treatment. Moreover, somatosensory and motor performance of the stroke-affected hand was significantly enhanced during TFD but not during placebo treatment. Thus, pharmacologically induced TFD of a stroke-affected forearm might improve the somatosensory and motor functions of the stroke-affected upper limb, accompanied by cortical plasticity.     

Major ozonated autohemotherapy promotes the recovery of upper limb motor function in patients with acute cerebral infarction

Major ozonated autohemotherapy is classically used in treating ischemic disorder of the lower limbs. In the present study, we performed major ozonated autohemotherapy treatment in patients with acute cerebral infarction, and assessed outcomes according to the U.S. National Institutes of Health Stroke Score, Modified Rankin Scale, and transcranial magnetic stimulation motor-evoked potential. Compared with the control group, the clinical total effective rate and the cortical potential rise rate of the upper limbs were significantly higher, the central motor conduction time of upper limb was significantly shorter, and the upper limb motor-evoked potential amplitude was significantly increased, in the ozone group. In the ozone group, the National Institutes of Health Stroke Score was positively correlated with the central motor conduction time and the motor-evoked potential amplitude of the upper limb. Central motor conduction time and motor-evoked potential amplitude of the upper limb may be effective indicators of motor-evoked potentials to assess upper limb motor function in cerebral infarct patients. Furthermore, major ozonated autohemotherapy may promote motor function recovery of the upper limb in patients with acute cerebral infarction.     

不同年龄卒中亚急性期患者上肢感觉与运动功能的关系研究

目的 探讨不同年龄卒中亚急性期患者上肢感觉功能与运动功能的关系.方法 前瞻性选取2020年6-12月于上海市静安区中心医院、上海市第三康复医院、河南大学附属南石医院连续收治的卒中亚急性期存在单侧上肢功能障碍的患者.记录患者的临床资料,使用Semmes-Weinstein单丝和两点辨别觉测试工具分别评估上肢的触觉和两点辨...     

The pyramidal tract in congenital hemiparesis: relationship between morphology and function in periventricular lesions

Three-dimensional MRI data sets were obtained from 12 young adult patients with congenital spastic hemiparesis caused by unilateral periventricular white matter lesions. The impact of these lesions on corticospinal projections to the upper and lower extremities was assessed on reconstructed semi-coronal planes following anatomical landmarks of somatotopic organization in the precentral gyrus and in the internal capsule: a more anterior plane running through the hand-knob of the precentral gyrus and the anterior portion of the posterior limb of the internal capsule representing projections to the upper extremity, and a more posterior plane running through the top of the precentral gyrus and the middle portion of the posterior limb of the internal capsule representing projections to the lower extremity. In addition, the total lesion extent was determined volumetrically, and Wallerian degeneration was assessed qualitatively in the internal capsule and quantitatively by measuring brainstem asymmetry. We found a strong correlation between motor dysfunction of the upper and lower limb and the lateral extent of the periventricular lesion measured on the respective semi-coronal planes. The total lesion volume and the degree of Wallerian degeneration correlated less strongly, both reaching statistical significance only with motor impairment of the hand.     

New directions in occupational therapy: implementation of the task-oriented approach in conjunction with cortical stimulation after stroke

Chronic upper extremity hemiparesis following stroke is a significant impairment that can limit a person's independence in all aspects of ADL, IADL, and functional mobility. Although recovery of functional independence may be more efficient using traditional compensatory techniques, these therapeutic methods often do not encourage integration of the hemiparetic arm and hand. In contrast, the task-oriented approach to motor recovery of poststroke hemiparesis emphasizes integration of the impaired limb into all functional tasks via skill-based training. Cortical changes have been documented following skill-based training of the upper limb in the healthy animal model. Additionally, the combination of subthreshold cortical stimulation combined with skill-based forelimb training in the induced-stroke rat model has demonstrated better outcomes than training alone. Preliminary research with human stroke survivors using task-oriented training and subthreshold cortical stimulation has shown promising results. The purpose of this article is to introduce an upper limb training protocol that was used in a national multisite trial that compares cortical stimulation in conjunction with taskoriented training to training alone.     

Does cortical motor neuron excitability change in peripheral nerve injury?

OBJECTIVE: To investigate changes in cortical motor neuron excitability after peripheral nerve injury, evoked spinal cord potentials (ESCPs) following hemispheric transcranial magnetic stimulation (TMS) were recorded in awake patients with unilateral brachial plexus injury. METHODS: ESCPs following hemispheric TMS were recorded in 6 patients with unilateral complete type brachial plexus injury. Studies were performed within 6 months from the time of injury. ESCPs were recorded from posterior epidural space using catheter electrodes. Hemispheric TMS was applied on the motor cortex using a figure-of-8 coil. The threshold of ESCPs following hemispheric TMS was measured. The number, latency, and amplitude of ESCPs following high stimulus hemispheric TMS were measured and compared. RESULTS: No significant change was observed in the threshold of ESCPs following TMS contra-lateral to the injured upper limb compared to that following TMS contra-lateral to the intact upper limb. Several ESCP components were recorded following high stimulus hemispheric TMS. No significant changes were observed in comparison with number, latency and amplitude of ESCPs following high stimulus TMS contra-lateral to the injured upper limb and those following TMS contra-lateral to the intact upper limb. CONCLUSIONS: From a study of ESCPs following single TMS, no evidence was obtained that cortical motor neuron excitability changes in patients with traumatic unilateral brachial plexus injury at relatively early stages. We investigated the changes of cortical motor neuron excitability in patients with brachial plexus injury from the ESCPs following TMS. In single TMS, our data gave no evidence for cortical excitability changes at relatively early stages.     

Cutaneous silent period in human immunodeficiency virus-related peripheral neuropathy

The aim of this work was first to determine whether the cutaneous silent period (CSP), a marker of small-nerve-fibre function, was altered in human immunodeficiency virus (HIV)-positive subjects with predominantly sensory symmetrical polyneuropathy and, second, to assess whether such alterations were predictive of an impairment in the largest calibre sensory and motor nerve fibres of the upper limb (UL) peripheral nerves. CSP was assessed in three groups of subjects: healthy control subjects, HIV-positive subjects with peripheral neuropathy (PN) of the lower limbs, and HIV-positive patients with clinical and neurophysiological involvement of the four limbs. CSP study showed a significant increase of the latency compared to the controls both in HIV-positive cases with no impairment in the UL (p=0.006) and in patients with four-limb neuropathy (p=0.002). CSP study in HIV-positive patients with mild lower limb distal sensory polyneuropathy can detect an early involvement of the UL peripheral nerves. CSP latency increase could therefore be addressed as the first sign of PN spreading to the UL.     

"Alien hand" and loss of bimanual coordination after dominant anterior cerebral artery territory infarction.

Three patients with dominant anterior cerebral artery territory infarction demonstrated a severe disturbance of upper limb motor control with impaired bimanual coordination, the "alien hand" sign, and intermanual conflict, in addition to signs of callosal interruption and a transcortical motor aphasia. Recordings of movement-related potentials in one patient showed an attenuated Bereitschaftspotential and a greater asymmetry of the NS' component of the premotor negativity with left finger than with right finger movement. The impairment of bimanual motor control and associated abnormal motor behaviour of the right hand in these cases are postulated to be due to involvement of the supplementary motor area and related areas of the medial frontal cortex.     

Postural rhythmic muscle bursting activity in Angelman syndrome

Postural impairment is one of the most consistent features of Angelman syndrome. Using multiple-channel electromyography, we studied a lower limb and an upper limb isometric postural task in 14 patients with Angelman syndrome and 18 unimpaired control subjects. Both tasks were associated with synchronous bursts of activity at frequencies of 6-8 s(-1) in all recorded muscles in all patients with Angelman syndrome and none of the control subjects. This pattern was not altered by extra-loading. Electroencephalogram recorded during the upper limb task showed no change in relation to the task. Burst-locked back-averaging of the electroencephalogram showed no spiking before or during the bursts. Various physiological and pathological rhythmic muscle activities have been proposed to be a manifestation of oscillations in the central nervous system and it has been suggested that such oscillations may have a role in the processing of motor commands. The mechanism of the rhythmic muscle bursting activity associated with maintaining posture in patients with Angelman syndrome is not clear, although it could be consistent with cerebellar Purkinje cell dysfunction, either as a pathological feature or as an adaptive process to overcome deficits in motor coordination.     

Abnormal corticomotor excitability assessed in biceps brachii preceding pronator contraction post-stroke.

OBJECTIVE: To assess corticomotor (CM) excitability of the antagonist biceps brachii (BB) post-stroke in preparation for pronator contraction. In healthy subjects, we previously demonstrated that prior to pronator contraction CM excitability of the antagonist BB was suppressed. METHODS: Transcranial magnetic stimulation (TMS) was used to assess pre-contraction changes in motor evoked potential (MEP) amplitude of the BB, when BB was acting either as an antagonist or an agonist. TMS was applied 100-200ms prior to rhythmic isometric BB or pronator contractions in chronic stroke survivors and age/gender matched healthy control subjects. RESULTS: Prior to pronator contraction, MEPs in BB were elicited in the stroke group but were absent in healthy controls indicating that CM excitability of the antagonist BB was increased post-stroke. The extent of the abnormal increase in excitability positively correlated with the extent of upper limb motor impairment. CONCLUSIONS: Our results suggest that an alteration of cortical control mechanisms regulating motor excitability of the antagonist BB may contribute to the impairment of upper limb motor coordination post-stroke. SIGNIFICANCE: This study offers a unique approach to study the potential for a cortical origin of post-stroke motor discoordination.